Die-head.



W. AI LEONARD.

DIE HEAD.

APPLICATION FILED OCT. 3. 915.

I LQ69,%6, Pat JllllGl, 8.

SHEETS-SHEE l.

Illa-" ammo z W. A. LEONARD.

DIE HEAD. APPLICATION FILED OCT. 8. 91s.

Lfiwfifiu Patented June 1 s.

2 SHEETS-SHE DIE-HEAD.

Specification of Letters Patent. Patented Julie iljl, 191%..

Application filed October 8, 1915. Serial No. 54,807.

To all whom it may concern:

Be it known that I, WILBun A. LEONARD, a citizen of the United States,residing at Woodmont, in the county of New Haven and State ofConnecticut, have invented new and useful Improvements in Die-Heads, ofwhich the following is a specification.

My invention relates to die-heads for screw cutting and the like, andparticularly to die-heads of that character employing radiallyadjustable dies movable into and out of threading position through themedium of a spring-retracted cam ring, which is automatically retractedat the limit of motion of the stock to move thedies out of engagementwith the work at the end of the threading operation.

In die heads of this character it is ad vantageous as well as customaryto have the cams at the front of the head, but this arrangement of thecams renders the cutting dies comparatively inaccessible, making itimpossible to apply or remove the dies without dismantling the parts toa greater or less extent at the expenditure of considerable time andlabor. In at least oneprior construction of device the dies are sodisposed as to be readily accessible, but the ring carrying the cams isarranged in rear of the dies and between the same and the head of thestock, making the construction to some extent objectionable on accountof an improper distribution of the cutting strains.

Theprimary object of my invention is to provide a die head embodying anovel dis tribution of parts whereby both the cam de vice and the diesare arranged at the front of the head so as to properly balance theparts and distribute the cutting strains, and wherein the dies. are alsoreadily accesslble, the construction being such as to permit of theapplication and removal of the dles, as wellas the assemblage anddisassemblage of the parts in genera in a ready and convenient manner.

The invention consists of the features of construction, combination andarrangement of parts herein fully described and claimed, reference beinghad to the accompanying drawings in which Figure 1 is a side elevat on,partially in longitudinal section, of a die-head embodying my invention,showing the dies in normal or retracted position.

Fig. 2 is a front elevation of the die-head.

Fig. 3 is a vertical longitudinal section through the head.

Fig. 4 is a view similar to Fig. 3 taken on a different vertical line.

Figs. 5, 6, 7, 8 and 9 are vertical transverse sections on the lines 55,6-6, 7-7, 8 -8 and 99 of Fig. 1.

Referring to the drawings, 1 designates the stock comprising the sleeve2 and head 3, which stock is mounted in practice by thesleeve 2 in aturret or holder which travels upon a suitable bed. The stock is heldfrom rotation in its movement, but feeds longitudinally upon the beduntil the limit of the threading operation is reached, at which time themovement of the stock is arrested by asuitable stop device, and thecutters are then thrown out of action to automatlcally stop thethreading operation. As shown, the head 3 is recessed to receive theshank 4 of a die carrying head or member 5, which is provided in itsouter or front face with guideways 6 for a series of radially movablecutters or dies 7 each having therein a groove or slot 8. Guide bolts 9connect the member 5 with the stock, to hold the parts connected and topermit the member 5 to have a certain degree of longitudinal slidingmotion with relation to the stock, coiled springs 10 being disposedabout said bolts and serving to hold the member 5 normally retracted.Radial grooves or guideways 11 and 12 are provided in the meeting facesof the parts 3 and 5 and receive keys 13 which lock the member 5 againstrotary motion on the stock, while permitting it to have the limitedlongitudinal sliding movements referred to.

Mounted for a limited rotary movement on the shank 4 is a setting ring14 provided with an operating handle 15 and a locking slot or recess 16,which slot or recess is arranged in alinement with an elongated slot 17in the head 3 and with a passage or opening 18 in an adjusting ring 19mounted to turn or rotate upon the shank 4. At its lower portion thering 19 is provided with a slot 20 into which projects a stop screw 21carried by the shank 4 of the head 5, the engaging surfaces of the ring19 and shank 4 being threaded for an adjustable engagement, as shown at22. Screws 23 and 24 carried by the ring 19 are disposed on oppositesides of the slot 20 and adapted to be adjusted into and out ofengagement with the screw 21, so that the ring 19 may be adjusted toadjust the dies for a definite cut, as hereinafter described. I Alocking bolt 25 provided with a manipulating handle 26 is adapted toengage the keeper slot or recess 16 in the ring 14 and is movablethrough the slots 17 and 18 in the members 3 and 19, said bolt beingnormally held projected by a spring 26 to lock the parts 14: and 19against relative rotation, said bolt also serving to limit the rotarymovement of the ring 19 with respect to the member 3. Upon retractingthe bolt 25, however, the ring 1 1 may be rotated by means of the handle15, and when the ring 14; is moved slidably forward so as to withdrawthe slot 16 from engagement with the bolt 25 said ring will also be freeto have rotary movement. The ring 1& carries a cam ring 27 detachablysecured thereto, as by means of screws 27 It will be understood that theadjusting ring permits, when said ring is released, of a rotary motionof the cam to a greater or less extent, determined by the position ofthe adjusting screws 23 and 24 with relation to the stop screw or member21. Also it will be understood that the adjusting ring, which is adaptedto turn with the cam ring and setting ring as a unit when the parts arefree for rotation, is normally held from rotary movement and preventssuch movement of the aforesaid parts as long as the locking bolt 25 isin engagement with the opening 18. It will also be understood that theslot or recess 16 permits of the normal setting movement of the camring, and that the parts are normally held in position againstlongitudinal separation by the bolts 9, springs 10 and keys 13.

In general practice the tool is mounted in a turret or other support,and this turret travels on a suitable bed whose traveling motion islimited by a desired type of stop device to determine the length of thescrew thread to be cut. When the limit of motion of the turret isreached, the stock is held thereby from further forward motion, but thecutters continue the cutting motion on the material being threaded,which is rotateol, and in consequence the cam ring and parts connectedtherewith continue to move forward against the resistance of the springs10, which are thereby tensioned, until the adjusting ring moves out ofengagement with the lockingv bolt, whereupon the cam ring and settingring are unlocked so asto permit the same to have rotary motion.

The cam ring forms a casing which incloses the dies and die carryingportion of the die carrying head or member 3, and this ring 27 isprovided at its outer side with a detachable face plate 28, secured inposition by screws 29, and which is preferably made removable so thataccess may be conveniently obtained to the internal parts for cleaning,oiling and other purposes. A

. and engages "the ring and die carrier head at its opposite ends, saidspring being tensioned when the cam ring is adjusted to project thedies, for the subsequent automatic retraction of the dies. The plate 28,which is a fixed part of the cam ring, is provided with cam projections31 which engage the grooves 8 in the dies7, whereby in the reverserotations of the cam ring the dies are adjusted in and out. Formed inthe cam ring are openings 32 through which the dies are adaptedto beremoved when the cam ring is turned to an abnormal predeterminedposition and the cam projections are disengaged from the cam grooves.

Formed in the perlphery of the die carrier head is a groove or recess33, the end walls of which form stops or abutments, and mounted upon thecam ring is a springprojected plunger 34chaving a finger piece 35, whichplunger projects into said recess. The circumferential length of therecess 33 is such as to normally control the extent of rotation of thecam ring on the die carrier head, which is sufficient to project andretract the dies but no more, and in such adlimit of retractive motionof the cam ring and dies the cam retracting spring 30 still remainsto acertain degree tensioned. The

plunger 34, however, may bemanually retracted by means of the fingerpiece 35, allowing'the spring 30 ,to retract or move the cam ring back.a still farther or abnormal distance, by which operation the camprojections 31 are moved clear of the grooves 8 in the cams 7 and theopenings32 in the cam ring brought into alinement'with the dies,allowing the latter to be removed therethrough in a readly andconvenient manner.

It will be evident from the foregoing description that the constructionis such as to adapt the cam ring to be mounted at the front, the diesthusbeing disposed between the stock andthe cam, by which an effective Ibalancing of the weights and the cutting strains secure an easy cuttingaction. Furthermore this arrangement adapts the cam to be applied andremoved with facility, and also adapts the cutters to be readily andconveniently detached without the necessity of dismantling or taking thecutter head apart, the advantages of which will be manifest. a

I claim A die head of the character described comprising a stock, a headcarried by said stock and having resiliently opposed longitudinalmovement thereon, radially movable dies in said head, a cam ringengaging said dies and having a peripheral flange inclosing said head, asetting ring revoluble upon said head within said flange, an adjustingring revolubly adjustable on said head, a spring pressed bolt extendingthrough an elongated slot in said stock and through said adjusting ringand having its end engaged within a recess in said locking ring, andmeans for holding said adjusting ring in adjusted position, said meanscomprising a stud threaded into said head and extending within a slot insaid adjusting ring, arranged alined screws in ring engaging said stud.

In testimony whereof I afiix my signature in presence of two Witnesses.

W'ILBUR A. LEONARD.

and oppositely 10 said adjusting Witnesses:

SARAH G. FARREN, ANNIE SANDS ANDERSON.

flames of thin patent may be obtained for five cents each, by addressingthe "commissioner of mam,

Washington, D. Q. t

